How about motorsport.. Motorcross for example.. How much air time does amateur motorcross get as opposed to pro level FMX for example? or go-karting/formula ford as opposed to the V8 supercars? The top end, contemporary stuff is what gets the punters interested..
I have seen Chris249's perspective repeated quite frequently on this forum (every post he makes it seems!), and while I agree that Wallys and one designs have, and had their place, and he's obviously very passionate about them, bringing up the historical boom in the 80s on this forum doesn't help the sport today.
As far as I can tell the "Back in my day sonny.." line only serves to turn off the younger generations. What will help is figuring out what will catch the eye of the future market, and running with it.
Kiting has us beat there - lots of bling, colour, and attitude. It's easy to learn, easy to transport and store, and you can rapidly see that the step from doing the beginner cruising stuff to the extreme dingle-dangle spinny stuff is as simple as not paying attention for 0.5 seconds.

None of that stuff applies to wally or OD gear. It's heavy, bulky, and lets face it, today's old

people used to do it.
The newer stuff has more bling factor, and we seem to be getting a bit more colour back too, but it is still bulky (compared to kiting), and requires more effort to get good(again - compared to kiting).
The plastic sit-on-top kayak market has taken over much of the 'Chris249 niche' where windsurfing was 'back in the day'.. they're bright colours, accessible, not overly energetic, can be used in stuff all wind, and the price is right for the market. And like the windsurfing equipment of old, there are plenty of them sitting in peoples sheds because the fad has passed. Not many of them have gone out and bought a whitewater kayak, or sea kayak as a result of the sit-on-top, but I bet that some of them were inspired to buy the sit-on-top by seeing one of those other more specialised genres of the sport.
I say don't blame the specialised genres - these things seem to have a natural lifespan... like flared jeans, and corduroy, and kiting.
Sure, flares and corduroy still work well as pants.. they're just not where it's at any more.